EASA AD No.: 2011-0104

EASA Form 110 Page 1/2 

## EASA AIRWORTHINESS DIRECTIVE

AD No.: 2011-0104

Date: 27 May 2011

Note: This Airworthiness Directive (AD) is issued by EASA, acting in accordance with Regulation (EC) No 216/2008 on behalf of the European Community, its Member States and of the European third countries that participat e in the activities of EASA under Article 66 of that Regulation.
This AD is issued in accordance with EC 1702/2003, Part 21A .3B. In accordance with EC 2042/2003 Annex I, Part M.A.301, the continuing airworthiness of an aircraft shall be ensured by a ccomplishing any applicable ADs. Consequently, no person may opera te an aircraft to which an AD applies, except in accordance with the requirements of that AD unless otherwise specified by the Age ncy [EC 2042/2003 Annex I, Part M.A.303] or agreed with the Authority of the State of Registry [EC 216/2008, Article 14(4) exemptio n].



### Type Approval Holder’s Name :

EUROCOPTER Type/Model designation(s) :
AS 350 and AS 355 helicopters

TCDS Number : EASA.R.008, EASA.R.146

Foreign AD : Not applicable

Supersedure : None



### ATA 65 Tail Rotor Drive – Tail Gearbox (TGB) Casing Assembly – Inspection / Replacement

Manufacturer(s): Eurocopter (formerl y Eurocopter France, Aerospatiale)

Applicability: AS 350 B, BA, BB, B1, B2, B3 and D helicopters and AS 355 E, F, F1, F2, N and NP helicopters, all serial numbers.
Reason: Following repair of the manufacturing mould for the TGB casing assemblies, the dye-penetrant inspection performed after machining of the attachment yokes of the control lever has revealed cracks on some TGB casing assemblies. EUROCOPTER identified the TGB casing assemblies which may show cracks. This condition, if not detected and corr ected, could lead to a crack on the attachment yokes of the control lever, possibly resulting in the loss of tail rotor pitch control and subsequent loss of control of the helicopter. For the reasons described above, this AD requires an inspection for cracks and, depending on findings, replacement of the TGB.

Effective Date: 10 June 2011EASA AD No.: 2011-0104

EASA Form 110 Page 2/2 Required Action(s) and Compliance Time(s): Required as indicated, unless accomplished previously: (1) Within the time indicated in Table 1 of this AD, identify the serial number of the TGB casing assembly P/N 350A33-1090-02 installed on the helicopter and, if the TGB casing assembly has a serial number as specified in Table 2 of this AD, inspect the attachment yokes of the control lever of the TGB casing assembly for cracks in accordance with the instructions of paragraph 3 of Eurocopter AS350 Alert Service Bulletin (ASB) 65.00.46 or AS355 ASB 65.00.22, as applicable to helicopter type. Table 1 Flight Hours (FH) accumulated by the TGB casing since new , on the effective date of this AD Compliance Time

Less than 550 FH Within 26 months or 660 FH accumulated by the TGB casing since new, whichever occurs first
550 FH or more Within 110 FH or 13 months, whichever occurs first after the effective date of this AD
Table 2 – Affected Serial Numbers TGB Casings
MA47577, MA47585, MA47587, MA 47588, MA47589, MA47590, MA47591, MA47592, MA47593, MA 47597, MA47598, MA47599, MA47600, MA47602, MA47604, MA 47606, MA47610, MA47613, MA47615, MA47617, MA47619, MA 47620, MA47621, MA47622, MA47623, MA47624, MA47626, MA47628, MA47631. (2) If, during any inspection required by paragraph (1) of this AD, any crack is detected on at least one of the c ontrol lever yokes of the TGB casing assembly, before next flight, replace the TGB with a serviceable unit in accordance with the requiremen ts of the Eurocopter AS350 ASB 65.00.46 or AS355 ASB 65.00.22, as ap plicable to helicopter type. (3) After the effective date of this AD, do not install a TGB casing with a serial number as listed in Table 2 of this AD on any helicopter, unless the attachment yokes of the control lever of the TGB casing assembly have passed the inspection as requir ed by paragraph (1) of this AD.

Ref. Publications: EUROCOPTER AS350 ASB No . 65.00.46 Revision 0, dated 18 May 2011, EUROCOPTER AS355 ASB No. 65.00. 22 Revision 0, dated 18 May 2011. The use of later approved revisions of these documents is acceptable for compliance with the requirements of this AD.

Remarks : 1. If requested and appropriately substantiated, EASA can accept Alternative Methods of Compliance for this AD. 2. The required actions and the risk allowance have granted the issuance of a Final AD with Request for Comments, postponing the public consultation process after publication. 3. Enquiries regarding this AD should be referred to the Airworthiness Directives, Safety Management & Research Section, Certification Directorate, EASA. E-mail ADs@easa.europa.eu

. 4. For any question concerning the technical content of the requirements in this AD, please contact: EUROCOPTER - Customer Service Technical Support Department - Aéroport de Marseille Provence 13725 Marignane Cedex - France. Tel: + 33 (0)4 42 85 99 51 - Fax: + 33 (0)4 42 85 99 66. E-mail: Directive.technical-support@eurocopter.com

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